As will be appreciated by those skilled in the art, the removal of crab meat from the shell structure of the crab body is still primarily performed by hand whereby each crab is handled several times as the meat is extracted. As is well known, although great care may be taken during the hand-picking of the crab meat, much meat is left in the shell structure, and a great number of shell fragments also finds their way into the meat.
In the past numerous devices have been developed which attempted to solve the problem of removing crab meat from the shell structure of the crab. For example, it has been known in the past to use centrifugal or spinning of crab bodies so as to extract the crab meat. For example, U.S. Pat. No. 1,175,037 issued Mar. 14, 1916 is a very early example of such centrifugal spinning to remove crab meat. In that patent a centrifugal retainer is used which has semi-circular receiving pans or receptacles for the meat as well as supports or racks for holding the sections of the animal to be shelled. However, before any effective use of centrifugal action for removing crab meat from a shell can be made, it has been found that initial preparation of the crab is required. To this end, U.S. Pat. No. 2,522,578 entitled "Recovery Of Crab Meat" shows a coring machine which processes the crab by producing a crab body core by making a circular cut through the ventrical surface of the crab body to the meat and skeletal parts within the body. After removing the core from the crab the meat is extracted by centrifugal action. Another patent which cores and centrifugally removes crab meat is entitled "Apparatus For Recovery Of Crab Meat" and has U.S. Pat. No. 2,525,604. Still another U.S. Pat. No. 2,771,630 is entitled "Crab Meat Extractor". According to teachings of that patent, after coring a section of the crab body from the crab, the cored section is rotated about its axis in order to removed the crab meat.
However, such coring of crabs for preparation has been found to be unusual wasteful of the more valuable body meat of the crab, and also results in a still significant amount of shell being left with the meat.
In an attempt to solve the many problems of such coring as preparation of crabs, U.S. Pat. No. 3,611,478 discloses a system whereby the crabs are initially cooked and then the back shells removed. After removal of the back shells, the bodies are cleaned and the claws and arms removed by manual operation. The clean bodies are then placed in a body slicing apparatus which sliced the bodies in half while simultaneously removing the central longitudinal partition of the crab to expose many of the meat containing compartments. The body halves were then placed into a centrifugal extractor for removal of the crab meat.
The preparation of crabs by means of the U.S. Pat. No. 3,611,478 still required a great deal of manual labor. To further automate the process U.S. Pat. No. 4,503,586 which is assigned to the same assignee as the present application teaches apparatus and methods for processing hard shell crabs. According to this patent the crab bodies are initially engaged and aligned, and then carried along a predetermined path by a conveyor holding means which maintains the orientation of the crab bodies during their movement through the processing operation. Trimming means are mounted along the path of travel for severing the claws and legs, and cleaning brushes are provided for removing the gills and other inedible materials. However, similar to U.S. Pat. No. 3,611,478 discussed above, a slicer is provided for cutting the trimmed and cleaned bodies into half sections which removes the central portions of the body. Unfortunately, by cutting through the main belly shell and removing the central partition in this manner there is still some loss of central body meat and some fragmentation of shell structure.
Thus a review of the prior art patents for preparing crab bodies for centrifugal extraction of the meat reveals that to date there has not been a simple and inexpensive process which can both rapidly process the crab bodies with minimum handling and which does not cause fracturing of the shell structure, nor result in objectionable loss of central body meat. Therefore, it is an object of this invention to provide methods and apparatus of preparing crab bodies with minimum loss of the natural strength of the crab shell structure and with minimum loss of edible meat.
It is still another object of the present invention to remove and trim the legs, claws and swimmerets from the crab body by automatic means.
It is yet another object of the present invention to provide apparatus and methods for substantially removing all gills and other inedible material from the crab body without leaving shell fragments or causing damage to the shell structure of the crab body.
Other objects and advantages will be obvious, and will in part appear hereinafter, and will be accomplished by the present invention which provides for methods and apparatus for preparing cooked crab for further processing to separate meat from shell by centrifugal action. The methods and apparatus of this invention comprise means for holding and releasably securing a cooked crab body in a particular and selected orientation with respect to the securing or holding means. The holding means is moved along a predetermined path toward a cutting means by a conveying means to which the holding means is attached. The cutting means, such as a pair of circular blades, makes a "V" cross-sectional shaped cut in the crab body which extends between the front and the rear of the crab. The open or top of the "V" shaped cut is located at the top or back of the crab and the "tip" of the "V" extends into the crab body such that the tip is proximate to but does not cut through the belly shell of the crab. This "V" cut thereby separates a "V" cross-sectional shaped portion containing the viscera of the crab from the crab body. At the same time, the "V" shape further opens certain closed meat compartments of the crab body allowing even better meat extraction during centrifugal separating action.
In a preferred embodiment, there is a second set of circular blades one each of which is parallel to a blade of the first set for removing the legs, claws and swimmerets of the crab adjacent the body and through the knuckle of such members. In addition, the preferred embodiment further includes means for brushing away the lungs and other inedible portions of the crab as it moves along the predetermined path.